Synthesis, solubility and optical properties of π-conjugated oligoelectrolytes derived from bis-thiophene-dialkoxyphenylene derivatives

Abstract

A new family of well-defined and fully conjugated oligoelectrolyte compounds were elaborated based on one or two bis-thiophene dialkoxyphenylene units. Di- or tetra-functionalized compounds with imidazolium, pyridinium and triethylammonium cationic species were synthesized in good yields. The effect of counteranions was also evaluated using iodide, chloride, fluoride and hexafluorophosphate anions. Their solubility was measured in apolar solvents (cyclohexane and chloroform) and polar protic solvents (water, ethanol, and isopropanol). A study of their thermal properties was conducted with TGA analysis showing a good stability up to 220 °C. Furthermore, their optical properties were examined and similar absorption properties were observed in solution and in the solid state. Most of these compounds exhibited significant fluorescence properties which were dependent on their involved counteranion and the solvent used.